//
// Handle.h
//
// Library: Data/ODBC
// Package: ODBC
// Module:  Handle
//
// Definition of Handle.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Data_ODBC_Handle_INCLUDED
#define Data_ODBC_Handle_INCLUDED


#include "Poco/Data/ODBC/ConnectionHandle.h"
#include "Poco/Data/ODBC/EnvironmentHandle.h"
#include "Poco/Data/ODBC/ODBC.h"
#include "Poco/Data/ODBC/ODBCException.h"
#include "Poco/Data/ODBC/Utility.h"
#include <sqltypes.h>


namespace Poco
{
namespace Data
{
    namespace ODBC
    {


        template <typename H, SQLSMALLINT handleType>
        class Handle
        /// ODBC handle class template
        {
        public:
            Handle(const ConnectionHandle & rConnection) : _rConnection(rConnection), _handle(0)
            /// Creates the Handle.
            {
                if (Utility::isError(SQLAllocHandle(handleType, _rConnection, &_handle)))
                {
                    throw ODBCException("Could not allocate statement handle.");
                }
            }

            ~Handle()
            /// Destroys the Handle.
            {
                try
                {
                    SQLRETURN rc = SQLFreeHandle(handleType, _handle);
                    // N.B. Destructors should not throw, but neither do we want to
                    // leak resources. So, we throw here in debug mode if things go bad.
                    poco_assert_dbg(!Utility::isError(rc));
                }
                catch (...)
                {
                    poco_unexpected();
                }
            }

            operator const H &() const
            /// Const conversion operator into reference to native type.
            {
                return handle();
            }

            const H & handle() const
            /// Returns const reference to native type.
            {
                return _handle;
            }

        private:
            Handle(const Handle &);
            const Handle & operator=(const Handle &);

            operator H &()
            /// Conversion operator into reference to native type.
            {
                return handle();
            }

            H & handle()
            /// Returns reference to native type.
            {
                return _handle;
            }

            const ConnectionHandle & _rConnection;
            H _handle;

            friend class ODBCStatementImpl;
        };


        typedef Handle<SQLHSTMT, SQL_HANDLE_STMT> StatementHandle;
        typedef Handle<SQLHDESC, SQL_HANDLE_DESC> DescriptorHandle;


    }
}
} // namespace Poco::Data::ODBC


#endif
